This ports the following barebox commit:

| commit 25e67cb
| Author: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
| Date:   Mon Sep 25 12:02:35 2017 +0200
|
|     remove checks for xzalloc() returning NULL
|
|     xzalloc() either returns memory or panics, so checking for NULL is useless.
|
|     Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
|     Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Ulrich Ölmann <u.oelmann@pengutronix.de>
Signed-off-by: Roland Hieber <rhi@pengutronix.de>